Grid winding machine



April 30, 1935. H, 1., COBB GRID WINDING MACHINE Filed June 15, 1931 INVENTOR HOWARD COBB BY '42 ATTORNEY Patented Apr. 30, 1933.":

UNITED STATES PATENT OFFICE GRID WINDING MACHINE Howard L. Cobb, Boonton, N. 3., assignor to Radio Corporation of America, a corporation of Delaware Application June 15,1931, Serial No. 544,386

8 Claims! (01. 140-11) This invention relates broadly to grid winding ins sp d The Pa t of'the shaft forming th machines and more particularly to a machine for spindle is provided with two grooves B for rewinding irregular grids. ceiving and supporting in position grid support- An object of the invention is to devise a mang m m rs or rid frame mem rs 40. A can b chine particularly adapted to wind grids for elec- 9 is provided and is adapted to slide over the free Ii tron discharge tubes. end of shaft 6. Cap 9 is constructed so as to act Another object of the invention is to devise as a gripping means for the grid frame members means for winding grids of an electron discharge 4!] when placed i the grooves 8. It should be tube having certain predetermined characterisnoted that the grOOVeS 3 n the Shaft 6 extend lid tics. I along the shaft 6 a small distance within the Another object of the invention is to devise sleeve member I. This, a is evident, the means for winding grids of electron discharge pu p of having the Sleeve member 5 form tubes for giving said tubes predetermined nove1 supporting surface for the other ends of the grid characteristics. frame members. While I have shown two grid it A specific object of the invention is to devise frame members ll) it is to be understood that 15 means for winding grids for so-called exponenthe grid const u y Call O y One tial tubes. more than two in which case the shaft 6 would Other objects of this invention will be apparent o ta t p p number of grooves from the following specification when read in Also suppo o the frame by means 0 a connection with the accompanying drawing, in supp rting m m I p vid another gear 20 which; 7 wheel l l adapted to mesh with the gear wheel 3.

Figure 1 generally illustrates a machine for Gear wheel ll also is adapted to mesh with a winding grids in accordance with my invention; second gear whe l It Supported u h h m Figure 2 is a detail of the machine shown in dium of shaft it on member l0. Shaft it has Figure 1 illustrating the cam controlled member; at one end a worm It which is adapted to cooper- 25 Figure 3 is an enlarged detail showing of the ate with worm wheel l5. Worm wheel I5 is fixedmachine illustrating the grid winding spindle; 1y suported by a shaft it. For the sake of sim- Figure 4 is an enlarged detail showing of a, plicity the supports and bearing members for the portion of the cam controlled'member including shaft it are not shown; however, it is to be disthe rack mechanism; tinctly understood that these supports may take 30 Figure 5 is an end view of the rack mechanism any desired form. One end of the shaft I6 is illustrating certain ,features thereof; adapted to form a support for a cam member ll Figure 6 is a sectional view along the line lie-b which cam member is adapted to rotate with of Figure 3; and, shaft i6. Fixedly attached on the frame II by 3:, Figure 7 illustrates a grid that may be wound means of member Hi I provide a rack mechanism by the mechanism shown generally in Figure 1. generally designated as It. The rack mechanism Referring to Figure 1 it will be seen that the comprises a fixed rack 20, Fig. i, and a movable machine comprises a framework l composed of rack 2|. The movable rack 2i cooperates with two supporting legs and a cross table member. the fixed rack ZOthrough the medium of a gear The framework i has provisions comprising screw wheel 22 which gear wheel meshes with the teeth 40 holes 2 for fixedly supporting the r'nechanism on of both racks 2t and 21!. One end of the movable a table or any other suitable foundation. A gear rack 2! is provided with a cam follower 23. Cam wheel 3 is rotatably mounted'on one of the legs follower 23 is adapted to cooperate with the cam of frame 8. Said gear wheel is provided with a surface of cam member H1 in well known manner.

5 handle l by means of which the operator may Gear wheel 22 is rotatably mounted to one end rotate the wheel. Operatively associated with of a sliding member 2% which member 2% is the gear wheel 3 and also mounted on the frame l adapted to slide between supports associated with I provide a gear wheel 5 having its teeth in enthe rack mechanism is as shown more in detail gagement with the teeth of wheel 3. Gear wheel in Figure 4. The other end of the sliding mema is mounted on a shaft 6 which has bearing on ber 24 is supported bya member 25 which is at- 50 the framework l. The said shaft b is provided 'tached to .the framework l in any desired manner.

with a sleeve member 1' adapted to maintain the Intermediate its supports, the sliding member 2t shaft. in the proper position with respect to the is provided with an adjustable cam block 26- The frame I. Shaft t protrudes through the sleeve 1 cam block 26 is slidably movable and rotatably intermediate the two supports and forms a windmovable with respect to the sliding member 24.

Cam lock 26 is provided with a groove 21 which groove extends partially around the cam block. For the purpose of locking cam block 26 in any desired position with respect to sliding member 24 I provide a lock screw 28 which operates to lock the cam block to member 24 in well known manner. In order to maintain the cam follower 23 in engagement with cam surface I1 I provide a spring 29 attached at one end to the rack mechanism I9 and at the other end to the shaft 24. Of course, it is to be understood that any other type of mechanism which is adapted to maintain the cam member and the cam follower in contact may be utilized. Mounted between the support members I provide a carriage support shaft 30 upon which is slidably and rotatably mounted a carriage 3 The carriage 3| has mounted thereon a guide support 32 comprising an upright member 33 and a horizontal member 34. The upper end of the upright member 33 is provided with a wire guiding wheel 35 while the outer end of the horizontal member 34 is provided with a wire guiding wheel 36. As is clear in the drawing, Figure l,-it will be seen that the groove 21 extending partially about the cam block 28 is adapted to cooperate with the inner edge of the vertical or upright member 33. Also mounted upon the carriage 3| I provide a wire guide arm 31. It will be seen that by means of the cam block 25 and the groove 21 cooperating with vertical member 33 there is provided an adjustment for the carriage 3|. In other words, by the mechanism thus far described it is possible to adjust the end of the guide arm 31 with respect to the shaft 3 as desired. As shown in Figure 1 the grid wire 39 is fed to the mechanism from a spool or other source not shown through wire guiding wheels 35 and 33 and guide arm 31. A spring 38 fixedly attached at one end to the table portion of frame I and at the other end to the carriage 3| is provided for maintaining the upright arm 33 always in contact with the cam block groove 21. It will be seen that with the arrangement shown and the cooperation existing between groove 21 and upright arm 33, the carriage 3| will be forced to move with the block 26 which in turn when locked to sliding member 24 is displaced in accordance therewith. For the purpose of welding the grid wire 39 to the grid frames 43 (see Figures 6 and 3) I provide a contact brush 4| adapted to cooperate with shaft 6. Brush 4| is mounted through suitable insulation means on the framework I. It is also desirable to mount the shaft 6 so as to be insulated from any other part of the machine except the brush 4|. By means of a conductor 42 and a switch 43, brush 4| is connected to one side of the battery 44. The other side of the battery is conductively connected to a roller 45 which has provided a handle 46 insulated therefrom. It will be seen that if the roller 45 is rolled along the grid frames 40 after the grid wire 39 has been wound around them, a current will flow through grid wire and grid frames with the result that the grid wire is welded to the frames. The sleeve member 1 is provided with two wire holding screws or members 41 which are adapted to hold the grid wire 39 in position during the winding operation.

With the rack mechanism shown it will be seen that the relative movement of rack 2| due to the cam l1 will be twice the corresponding movement of the carriage 3|. This construction makes possible a more accurate winding mechanism since the cam may be made to have larger dimensions. It is, of course, evident that errors in manufacturing the cam would be proportionally smaller in a large cam than in a smaller one.

In practice I have found that with the same cam, grids giving tubes widely varying characteristics may be made by simply changing the distance between the overhanging end of guide 31 and the spindle shaft 6. This may be done by loosening screw 28 and turning cam block 23 about member 24. 7

It is to be understood that the cam I1 which I have shown in the drawing is merely illustrative of an infinite number of cams having varying shapes that may be employed. As inferred heretofore the spacing of the grid windings may be made to vary in any desired manner by simply changing the cam. The cam may be removed by unscrewing nut 48 and a new cam substituted.

Roughly speaking the cam shown in Fig. 1 will wind a grid such as shown in Fig. 7. p

The operation of my device is as follows:

Cap 9 is removed from the end of shaft 6 and two grid support wires 40 are inserted in the two grooves on the shaft 6, care being taken that one end of each of the grid support wires is inserted in the respective hole provided for in the sleeve 1 as clearly shown in Fig. 3. The cap 9 is then replaced over the end of the shaft in such a way that the two grid support wires 40 are clamped in position. The gear wheel 3 is then turned by means of handle 4 a distance sufficient to place the cam at the starting position. For convenience, the cam may be marked in any desired manner so as to indicate the position that it should occupy at the start of a winding cycle and also marked so as to indicate the position it should occupy. After the cam is properly placed in the correct starting position wire 39 is drawn from the supply through the guide wheel 35, guide wheel 36, guide arm 31 and placed around wire holding members 41 where the wire is held in position. The distance of arm 31 from the shaft 6 is then adjusted by means of the cam block 26 to whatever position is desired. The operator then turns the gear Wheel 3 by means of handle 4 until a marker on the cam l1 comes opposite the proper end variable depending upon the cam surface. When.

the grid has been wound the operator takes the roller 45 and places it at one end of one of the grid support wires 40, contact 43 is then closed and roller 45 is rolled along the length of the wire 40. It will .be seen that the current pass- .ing through the circuit will weld the smallgrid wires to the grid support member 40. The same is done to the other grid wire 40 after which the cap 3 is removed and the wound grid and supports 40 slid out of the shaft 6. The loose wires at both ends of the grid may be cut off or broken off. I have found that it is better practice to place the roller against the wire support 40 before switch 43 is closed as otherwise it is likely that a. spark will jump between the roller and the grid support wire before the two come in contact. tensity to melt the wire and thus break the grid structure. After the grid has been removed the machine is turned again until the cam is in the correct starting position after which the machine is ready to wind another grid.

While I have shown only one embodiment of This spark is usually of sufficient, in-' applied in coil winding apparatus as well as grid winding machines and in fact in any system that may require a winding operation.

I claim:

1. In a grid winding machine, a winding spindle having provision for holding at least one grid support wire, rotating means for rotating said spindle at a velocity proportional to the velocity of said rotating means, means comprising a carriage and guide arm for feeding a continuous strip of grid wire longitudinally of said spindle during the rotation thereof whereby said wire is wrapped about said spindle, means for varying the distance between said guide arm and said spindle comprising a cam block and means including said cam block for producing a variable velocity of longitudinal motion of said guide arm' relative to said spindle for varying the concentration of said grid wire thereon.

2. In a machine of the kind described a mandrel having means adapted to receive a supportabout said mandrel in contact with the support wire, a cam controlled means for producing a variable velocity of 4 longitudinal motion of said carriage and guide arm relative to said mandrel for varying in predetermined fashion the concentration of said wound strip thereon and means acting upon said carriage for determining the distance between said guide arm and said mandrel whereby the characteristics of said wound strip may be varied independently of said cam.

3. In a grid winding machine, a winding spindle having at least one groove extending longitudinally thereof for receiving a grid support wire, means for clamping the support wire on said spindle so as to maintain it in position within the groove, rotating means for rotating the spindle at a velocity proportional to the velocity of the rotating means, a carriage, a guide arm mounted on the carriage, said guide arm beingadapted to guide a continuous strip of grid wire longitudinally of said spindle during rotationthereof, means comprising a cam adapted to be operated by the rotating means for producing a variable velocity of longitudinal motion of the carriage along the spindle with respect to the velocity of the rotating means for varying the concentration of the grid windings around the spindle and means comprising a current source,

, the spindle shaft and a roller device for welding the grid wire to the grid support wire.

4. A grid winding machine comprising a winding spindle having provision for holding at least one grid support wire thereon, rotating means for rotating the spindle at a velocity proportional 7 so as to produce a variable velocity of longitudinal motion of the carriage along the spindle with respect to the velocity of the rotating means for varying the concentration .of the grid windings about the spindle in predetermined fashion depending upon the shape of the cam and means for adjusting the distance between the guide arm and the spindle whereby the characteristics of the wound grid may be varied independently of variation caused by the cam.

5. The subject-matter recited in the next preceding claim in combination with an electrical circuit including at least a portion of the spindle for passing an electric current between the grid windings and the grid support wire whereby the grid wire is welded to the gridsupport wire.

6. In a grid winding machine, a winding spindle having provision for holding at least one grid support wire, rotating. means for rotating the spindle at a velocity proportional to the velocity of therotating means, means comprising a carriage and a guide arm for feeding a continuous strip of grid wire longitudinally of said spindle during the rotation thereof whereby said wire is wrapped about said spindle, means for'varying the concentration of the grid wire on said spindle to thereby vary the characteristics of the grid comprising means for varying the distance between the guide arm and the spindle including a earn block and means including said cam block for producing a variable velocity of longitudinal motion of said guide arm relative to the spindle.

'7. In a machine of the kind described a frame, a rotary winding mandrel mounted on the frame, a grid wire guide movably mounted on the frame to travel lengthwise of the mandrel, a cam mounted ona shaft journaled in the framework, a cam follower and means for connecting the cam follower to the grid wire guide whereby movements of the cam follower are imparted to the grid wire guide said cam having a contour which will vary thespeed of travel of the grid wire guide along the mandrel so as to make a variable pitch grid, and a driving mechanism for driving the -mandrel and cam in synchronism.

8. The device described in the next preceding claim further characterized by that the means for connecting the cam follower to the grid wire 

